A variable when it appears for the first time is introduced with the keyword var, after that you put in the variable name
var ourVar;
You could stop here or you may want to give a value to the variable. To give a value to the variable you put the assignment operator = to the right of the variable name and then after that the value you want to assign to the variable
var ourVar = 19;
Now you just need to do the same creating a variable named a and giving it a value of 9 like asked in the challenge